Area of Circles Review

What is the formula to find the area of a circle?

• A = πd

• A = 2πr

• A = πr²

• A = xyz

What is the area of this circle?

• 82.13 m²

• 78.50 m²

• 314.16 m²

• 170.12 m²

A clock face has a diameter of 10 inches. What is the approximate area of the clock face in square inches?

• 314 in²

• 31.4 in²

• 7.85 in²

• 78.5 in²

Hannah drew a circle with a radius of 30 cm. Jonas drew a circle with a radius of 20 cm. What is the approximate difference in the areas of their circles?

• 2,826 cm²

• 1,570 cm²

• 1,256 cm²

• 314 cm²

What is the diameter?

• 8

• 16

• 10

• 4

What is the radius?

• 18

• 72

• 38

• 14

What does d represent in the formula: C = π·d

• diameter

• radius

• pi

• 3.14

Alex has trained his puppy, Popper, to jump through a ring. According to Alex's measurements and calculations, the ring has a diameter of 3.5 feet. What is the ring's circumference (use 3.14 for pi)?

• 11.32 ft

• 12.25 ft

• 10.99 ft

• 8.75 ft

The Jones family wants to enclose their circular garden with a fence. To the nearest foot, what is the minimum length of fencing they need to buy?

• 56.25 ft

• 246 ft

• 365 ft

• 393 ft

The diameter of the face-off circle on an ice-hockey rink is 30 feet. Find its area.

• 675.6 ft²

• 29.67 ft²

• 545.8 ft²

• 706.5 ft²